If she decides against Ireland, Apple faces potentially huge bills for back taxes.

Mr Noonan met Ms Vestager while he was in Brussels for a meeting of European Finance Ministers. The Apple case is thought to have been discussed, although the precise details of the conversation have not been made public. The Department of Finance confirmed the meeting took place, but gave no further details.

US treasury secretary, Jacob Lew, is reportedly also set to meet with Ms Vestager this week, four months after he complained to her about the EU unfairly targeting US multinational firms trading in Europe. Ms Vestager has denied the claims.

A Bloomberg report claimed that the Commissioner's team has now come up with two positions on how much tax Apple owes in Ireland.

The newswire also said Mr Lew has contacted Ms Vestager ahead of her final ruling, urging her to avoid ordering any collection of back taxes from Apple.

The EU opened the Apple probe in 2014, and, in preliminary findings, said its tax arrangements were improperly designed to give the company a financial boost in exchange for jobs in Ireland. The Irish government has said it will "vigorously defend'' any adverse Apple tax decision.

Apple told a European Parliament panel earlier this year that it has "paid every cent of tax that is due in Ireland".

Mr Noonan said last month the EU decision could come as soon as July, though he also suggested that the UK vote to quit the EU may trigger delays. The finance ministry couldn't comment on timing.

Ms Vestager has remained tight-lipped about the possible amount that Apple could be ordered to pay back to Ireland should regulators decide that the company received illegal tax breaks.

Estimates from banks have varied from hundreds of millions of euro to billions.

A spokesman for Apple declined to comment on the timing of the decision.

The company has previously claimed that its operations in Ireland support 18,000 jobs and that it spent over €200m with Irish companies last year. It also claimed it has spent over €11bn with 4,500 European suppliers supports 240,000 jobs in Europe.

Apple is Cork's largest private employer where its facility has operations in service, sales, finance and logistics. Its Cork factory, employing more than 5,500 people, is the only Apple-owned manufacturing facility in the world.